#include "dataprotocol.h"
#include <Qdebug>
#include <cstring>


static uint8_t index = 0;
// 协议帧格式
typedef struct
{
    uint8_t head_h;
    uint8_t head_l;

    uint8_t index;
    uint8_t index_xor;

    uint16_t len;
}iap_rx_header_rt;


DataProtocol::DataProtocol(QObject *parent)
    : QObject(parent)
{
}


QByteArray DataProtocol::packData(const QByteArray &data)
{
    QByteArray packet;
    packet.append(0xAC);
    packet.append(0x6D);
    packet.append(++index);
    packet.append(index^0xFF);
    packet.append((static_cast<int>(data.size()))&0xFF);
    packet.append((static_cast<int>(data.size()) >>8 )&0xFF);
    packet.append(data);
    uint16_t cal_crc = crc16((reinterpret_cast<const uint8_t*>(packet.constData())), packet.size());
    packet.append(static_cast<char>(cal_crc & 0xFF));
    packet.append(static_cast<char>((cal_crc >> 8) & 0xFF));

    qDebug() << "QByteArray content will send hex: " << packet.toHex().toUpper();

    return packet;
}

//                      0  1  2  3  4  5  6  7  8  9  10 11 12 13
// 1.获取设备信息			AC 6D 00 FF 06 00 10 80 01 02 03 04 90 6B
QByteArray DataProtocol::unpackData(const QByteArray &packet)
{
    if (packet.size() < 14)
    {
        return QByteArray();    // 数据包不完整
    }

    iap_rx_header_rt iap_rx_header;
    std::memcpy(&iap_rx_header, packet.constData(), sizeof(iap_rx_header_rt));

    // 检查起始符
    if ((iap_rx_header.head_h != 0xAC) || (iap_rx_header.head_l != 0x6D)
            || (iap_rx_header.index != (iap_rx_header.index_xor^0xFF))
            )
    {
        qDebug() << "帧头错误";
        return QByteArray(); // 帧头错误
    }

    if (iap_rx_header.index != index)
    {
        qDebug() << "帧序列错误";
        return QByteArray();
    }

    uint16_t len = iap_rx_header.len;

    const uint8_t *data_hex = reinterpret_cast<const uint8_t*>(packet.constData());
    uint16_t cal_crc = crc16(data_hex, (iap_rx_header.len+6));
    uint16_t rec_crc_frame = ((data_hex[iap_rx_header.len+7]<<8) | data_hex[iap_rx_header.len+6]);
//    qDebug() << "unpackData hex111: " << packet.toHex();
    qDebug("len: %d", len);
    if (rec_crc_frame != cal_crc)
    {
        qDebug("crc err: 0x%04x, 0x%04x", rec_crc_frame, cal_crc);
        qDebug() << "crc错误";
        return QByteArray();
    }

    QByteArray data = packet.mid(6, len);
//    qDebug() << "unpackData hex222: " << data.toHex();

    return data;
}


// CRC-CCITT lookup table  Polynominal = 0x1021   初始值为0x0000
// X^15+X^12+X^5+1
// 此table 用于协议处理crc16 计算
static const uint16_t sc_protocol_ccitt_crc_table[256] =
{
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
};

uint16_t DataProtocol::crc16(const uint8_t *p_buff, uint32_t len)
{
    uint16_t initial_crc = 0x1D0F;
    while(len>0)
    {
        initial_crc = (initial_crc << 8) ^ sc_protocol_ccitt_crc_table[ ( ( initial_crc>>8 ) ^ *p_buff ) & 0xff ];
        len--;
        p_buff++;
    }
    return initial_crc;
}
